Becky Kuhn, M.D., answers the top ten questions about HIV tests:
1) How do HIV tests work?
2) What are the window period and false negatives?
3) How long after exposure to HIV does it take for a person to test HIV positive?
4) What's the risk of a false positive on the initial ELISA test?
5) What's the risk of a false positive diagnosis after a Western Blot test?
6) Can I be tested for free?
7) Can I be tested without revealing my name?
8) Do I have to be stuck with a needle?
9) If I test HIV positive, does that mean Im going to develop AIDS and die?
10) Why should I get tested?
She also explains: anonymous testing; confidential, name-based testing; home-based testing for HIV-1; and use of the PCR Test for detection of HIV infection during the window period. There is a 98.5% chance that an "HIV positive" result on an initial ELISA test is correct (and a 1.5% chance that it was a false positive). There is a 99.9996% chance that an "HIV positive" result after an initial ELISA *and* a confirmatory Western Blot test is correct (and 1 chance in 250,000 that it was a false positive). HIV denialists (people who deny that HIV is the cause of AIDS) often exaggerate the frequency of false positives and ignore the fact that a person must get an "HIV positive" result on BOTH the initial ELISA *and* the confirmatory Western Blot test before the person is given a diagnosis of "HIV positive." If you have taken both an ELISA test and a Western Blot test and your doctor tells you you are HIV positive, believe them!